同位素稀释-气相色谱-质谱联用法分析烟气中性香味成分

建立了同位素稀释-气相色谱-质谱联用法（ID-GC/MS）测定烟气中香叶基丙酮等10种痕量中性香味成分的含量。在捕集烟气粒相物的剑桥滤片上加入 10 种中性香味成分对应的同位素标记物，经同时蒸馏萃取并分离得到中性香味成分，采用优化后的 GC/MS 条件进行分析，通过对比同位素标记物的分子离子、特征碎片和标准品的保留时间定性鉴定复杂体系中的香味成分；同时，以同位素作内标，在SIM 模式下进行定量分析。结果表明，各成分的线性相关系数r均大于0.999 0，方法检出限(LOD)为0.34～4.59 μg/kg，定量限(LOQ)为1.14～15.30 μg/kg，平均回收率在83.3%～106.6%之间，相对标准偏差（RSD）在0.15%～8.69%之间。该方法的灵敏度和准确度高，重复性好，可为复杂基质中痕量成分的定性和定量分析提供可靠、准确、简便的方法。

Neutral Aromatic Components from Cigarette Smoke by Isotope Dilution-GC/MS

A method of isotope dilution-gas chromatography-mass spectrometry (ID-GC/MS) was developed for analysis of 10 kinds of neutral trace aromatic components (benzaldehyde, 6-methyl-5-hepten-2-one, furfuryl acetate, methyl benzoate, isophorone, 2,4-dimethyl-acetophenone, 2-undecanone, geranyl acetone, β-ionone and benzyl benzoate) from cigarette smoke. 10 isotope markers (D₅-benzaldehyde, ¹³C₃-6-methyl-5-hepten-2-one, D₃-furfuryl acetate, D₅-methyl benzoate, D₈-isophorone, D₃-2,4-dimethyl acetophenone, ¹³C₃-2-undecanone, ¹³C₃-geranyl acetone, D₄-β-ionone, D₅-benzyl benzoate) corresponding to neutral aromatic components were added to Cambridge filter for collecting particles of cigarette smoke，and the aromatic components were extracted by simultaneous distillation and extraction method. The acidic and basic components in the extract were removed by washing with 5% hydrochloric acid and 5% sodium hydroxide aqueous solution (concentrations of volume percent), respectively, and the neutral components extract were obtained. The neutral aromatic components were analyzed by GC/MS under optimized conditions. The molecular ions and characteristic fragment ions with isotope atoms of isotope markers were selected as qualitative ions in qualitative identification in order to identify the corresponding target components. The qualitative identification of the target components in extract was assisted by the labeling effect of isotopes because of the addition of isotope markers, and the neutral aromatic components were identified reliably by comparing with characteristic fragments of isotope markers and retention time of reference standards in complex system. Many separation methods such as solid-phase microextraction (SPME) and preparative HPLC were omitted from the samples pretreatment process and the sample consumption was rather reduced. Two quantitative ions with higher signal-to-noise ratio and less interference were selected for each compound in quantitative analysis. The target neutral components in extract were analyzed by GC/MS using quantitative ions in SIM mode, and the results showed that the separation of target compounds from interfering components was completely and the accurate quantitative analysis could be carried out. The contents of 10 neutral components were simultaneous determined by internal standard curve method using corresponding isotopes as internal standard. The analysis results showed that the correlation coefficients are greater than 0.999 0, the limits of detection (LODs) are 0.34-4.59 μg/kg, and the limits of quantity (LOQs) are 1.14-15.30 μg/kg. The average recovery is in the range of 83.3%-106.6%, and the relative standard deviations (RSDs) are in the range of 0.15%-8.69%. This method is sensitive and accurate，which is suitable for quantitative analysis of neutral aromatic components in cigarette smoke.